It was a finger trap! If you put both "pointer" fingers in ... one in each end, and pull, your fingers are trapped. The puzzle is how to get out of the trap. (Actually, you just have to compress the puzzle to release the pressure and your fingers ... it isn't easy to do with no hands free, but if you have a friend to help, it's a snap.) We used to get these as prizes at the arcade when I was a child.

Leave it to the Peanut gallery to comment and solve the problem. You can tell Peanut is sighing and shaking his head resignedly "Hoomins, nothing better to do with their fingers than getting them stuck. Then they don't even have the teeth to chew themselves free. Good thing I hopped by to check on their bunchores, can't leave them alone for a minute."